Mercury switch breaker



Dec. 31, 1940. J. H. STALEY MERCURY SWITCH BREAKER Filed Aug. 8, 1958[771/677 207" do 6 6 0 L7 /7 /1 Sin/ex mm 'z'fiorneys Patented Dec. 31,1940 PATENT orrics MERCURY swrrorr BREAKER Joseph H. Staley, Columbus,Ind.

Application August 8, 1938, Serial No. 223,625

4 Claims.

' This invention relates to the art of mercury switches and particularlyto that type employing a refractory member through or over which acolumn of mercury is severed to break the 5 circuit, the refractorymember being employed to control the location and quenching of theensuing arc. The primary object of the present invention is to provide arefractory member for the purpose indicated which will have a formlending itself to insertion within a tubular member in conjunction withan iron or metal wall chamber at one end and an electrode at the otherend, the structure being so arranged that a pool of mercury may bemaintained in contact with the electrode without after spill so thatonce the circuit is broken, it will not be made by subsequent flow ofmercury from that pool which might otherwise result upon further tiltingor rocking of the switch.

The objects and advantages of the invention will be better understood bythose versed in the art from the following description of the inventionas illustrated in the accompanying drawing, in which Fig. 1 is a centrallongitudinal section through a structure embodying the invention, in theclosed circuit position;

Fig. 2, a similar view in open circuit position, and

Fig. 3, a view in perspective of the refractory member.

Like characters of reference indicate like parts throughout the severalviews in the drawing.

Reference is made to my co-pending U. S.

patent application Serial Number 708,844, filed January 29, 1934, ofwhich the present application is a continuation in part.

Referring to the drawing, in the particular embodiment of the inventionherein illustrated,

a metallic tubular body It] is employed with a closed end H and a cap I2is telescoped over the end of the body it to have an intervening,insulating sleeve IS. The cap 12 forms one electrode and the body it theother. A refractory member l4, hereinafter called a breaker forconvenience, is formed to have a generally cyiindrical shape so as to befrictionally engaged within the end of the sleeve l3 to be between thecap l2 and'the body IS in respect to flow of mercury therebetween. Thisbreaker I4 is made out of any suitable material which will withstand thetremendous heat of the electric are without any appreciabledeterioration 55 and particularly as will not deteriorate to such anextent as will cause any breaking down thereof to have particles ormaterials therefrom, mixing with the mercury. I Theparticulararrangement of the breaker is important. It has a major internal bore 15opening into the chamber of the body Iii. It also has a minor bore l6co-axial with the bore 15. This smaller bore it is at that end of thebreaker M which is nearest to the end wall of the cap l2. There is thefurther important feature in connection with this breaker M of theextending boss ll that has an external diameter less than that of themajor portion of the breaker, and through which boss 5'! the bore I5 iscarried. This structure provides an abrupt annular shoulder It at thejunction of the minor bore It with the major bore l5, this shoulderbeing well back within the breaker at the internal end of the bore 15.The other important feature of this structure is that by reason of theextending boss E1, the open end of the bore l6 may be carried in closeproximity to the end wall of the cap l2 and at the same time there willbe left between the breaker and the cap I2 a chamber l9. around the bossH, in which chamber a sufficient quantity of mercury 2i] may be retainedregardless of the angle of tilting of the entire switch which will carrythe current between that mercury and the cap l2 without heating beyond apredetermined amount. Also, as indicated in comparing Figs. 1 and 2,when the switch is tilted from the closed position in Fig. 1 to the openposition in Fig. 2, there will be no subsequent flow from this body ofmercury 20 to the major body 2| since further tilting will only causethe mass of mercury 20 to extend further around the periphery of theboss ll.

The present application is directed toward this breaker M in its generalassociation with a twopart metallic switch irrespective of the sealingelectrode employed in conjunction with the tubular body Ill, thissealing electrode in the present instance being in the form of thetelescoping cap although the invention is not intended to be limited tothat particular form.

As indicated in my co-pending application, Serial Number 708,844, abovereferred to, the bore I5 is so proportioned as to length, diameter, andspacing from the electrode [2 as to properly define the location of thebreak between the minor and major masses of mercury 20 and 2| wherebythe ensuing arc will occur, within this smaller bore l6 and thereby besubject to the quenching effects produced.

While I have herein shown and described my invention in the oneparticular form, it is obvious that there may be structural variationswithout departing from the spirit of theinvention and I, therefore, donot desire to be limited to that precise form beyond the limitations asmay be imposed by the following claims.

I claim:

1. In a mercury switch having a quantity of mercury and a pair ofelectrodes, one of which forms a tubular metallic chamber, a breakerpositioned between the electrodes and in which the mercury flows tocomplete and break a circuit between the electrodes, said breaker havinga cylindrical bore of substantially the same size of and leading fromthe said electrode chamber, an extension on the breaker of externaldiameter less than that of the breaker and having a second cylindricalbore of less diameter co-axially leading from the larger bore throughsaid extension and opening concentrically of and toward the,

other electrode.

2. In a mercury switch having a quantity of mercury and a pair ofelectrodes, one of which forms a tubular metallic chamber, a breakerpositioned between the electrodes and in which the mercuryflows tocomplete and break a circuit between the electrodes, said breaker havinga cylindrical bore of substantially the same size of and leading fromthe said electrode chamber, and having a second cylindrical bore of lessdiameter co-axially leading from the larger bore and openingconcentrically of and toward the other electrode, said breaker furtherhaving a boss extending from that end having the smaller bore, whichbore continues through the boss, the boss having an external diameterless than that part of the breaker having the major bore, saidboss'being proportioned in relation to the other electrode to extendtherein in spaced relation.

3. For a mercury switch, an insulating and arcresisting member having amajor cylindrical bore open from one end and terminating at its otherend at a transverse wall, said member further having a minor cylindricalbore concentric of the major bore axis through said wall and opening atits end removed from the wall, said transverse wall being planer andnormal to said axis defining a sharp shoulder about the minor boreorifice through the wall, and a boss having an external diameter reducedfrom that of the breaker and through which said boss said minor boreextends.

4. For a mercury switch, an insulating and arcresisting member having amajor cylindrical bore JOSEPH H. STALEY.

